Some extreme ultraviolet (EUV) radiation production devices have a vacuum chamber in which a target material can be introduced to produce EUV radiation. A beam guiding chamber serves to guide a laser beam from a laser source into the vacuum chamber. Between the vacuum chamber and the beam guiding chamber an intermediate chamber is provided. A first window that closes the intermediate chamber in a gas-tight manner serves to introduce the laser beam from the beam guiding chamber into the intermediate chamber. A second window that closes the intermediate chamber in a gas-tight manner serves to discharge the laser beam from the intermediate chamber into the vacuum chamber.
The vacuum chamber is separated from the environment in a sealing manner by the second window. If the second window is destroyed or the seal of the second window is faulty, gas from the environment can flow into the vacuum chamber since in the vacuum chamber there is a lower pressure than in the environment, for example, in the beam guide. The second window or the seal thereof consequently constitute potential sources of leakage. Owing to a non-tight window, it is possible not only for gas, but also where applicable for fluid materials, for example, cooling water for cooling the window, to reach the vacuum environment. In some cases, the primary sealing of the vacuum chamber by the second window is supplemented with a secondary sealing by the first window so that, in the event of damage to or breakage of the second window, only the (small) gas volume present in the intermediate chamber can reach the vacuum environment.
In some systems, a device has an optical component having a non-planar surface which includes an optically active region. A flow guide is formed on the non-planar surface to orientate a gas in order at least in a part-region of the optically active region of the non-planar surface of the optical component to produce a turbulent flow to cool the optical component. The optical component may, for example, be a convex lens which serves to introduce a laser beam into the vacuum chamber of an EUV radiation production device and which focuses the laser beam in a target region within the vacuum chamber.